Sindarin changed more than most Eldarin tongues, and it is useful to distinguish a separate stage of development for that language, as it developed from Ancient Telerin into Sindarin. Tolkien called this stage “Old Sindarin” (roughly analogous to Old Welsh), and it may have been the language as it was spoken shortly before the Noldor arrived in Beleriand. With the death and disruption of the wars against Morgoth, the language of these Elves underwent exceptionally rapid change over the next few centuries.